Based upon personal experience and literature the authors briefly discuss the usefulness of arteriography, ultrasonography, CT and MR in the diagnosis of aortic dissecting aneurysms. In the diagnostic algorithm concerning aortic dissection type I and II acc. DeBakey, the initial diagnostic method should be echocardiography, followed by CT or MR or eventually aortography. In the case of type III aortic dissection the authors recommend transesophageal echocardiography and CT or MR or eventually aortography as the last examination.